1. Field
The field is photographic illumination, and in particular reflectors and diffusers for light emanated by photographic flash lamps.
2. Prior-Art Diffusers and Reflectors
The following is a list of some prior art that presently appears relevant:
PatenteePatent or Pub. Nr.Kind CodeIssue or Pub. Dateor Applicant2910573B11959-10-27Bing et al.3258586B11966-06-28Blizzard4078170B11978-03-07Sloop4099221B11978-07-04Carrillo4122333B11978-10-24Crouse4194234B11980-03-18Geissler4233648B11980-11-11Geissler4242616B11980-12-30Takematsu4272169B11981-06-09Stone4380787B11983-04-19Stone4539624B11985-09-03Stone4777566B11988-10-11Lowell et al.5136312B11992-08-04Weaver et al.5194885B11993-03-16Spencer5337104B11994-08-09Smith et al.5778264B11998-07-07Kean6234638B12001-05-22Beverly6614999B22003-09-02Hagiuda
Flash lamp diffusers and reflectors are used in photography to produce various lighting effects. A simple, forward-facing flash lamp and reflector are used in low-cost cameras to illuminate the subject being photographed. While such an arrangement provides an adequate light level for a photograph, the resultant image is often over-illuminated at the center, under-illuminated at the edges, and contains shadows.
Improved results are obtained when light from a flash lamp is reflected from a surface, such as a ceiling, before reaching the subject. This type of illumination is called a “bounce flash”. The reflected light effectively emanates from a larger source than the flash lamp itself, resulting in more uniform illumination of the subject. A diffuser can be added to the flash lamp assembly to further smooth variations in light as it strikes the subject.
Bing et al. show a bracket that is interposed between a camera and a flash lamp assembly. Without the bracket, the flash assembly mounts on the camera so that the light from the flash is projected along a line parallel to the lens axis. With the bracket, the flash assembly is repositioned so that its light is projected perpendicular to the lens axis and typically aimed at a ceiling. While this apparatus eliminates direct illumination of a subject, light emanates from this apparatus in only a single direction, thereby providing limited bounce capabilities.
Carrillo shows a reflector assembly and flash lamp mounting bracket combined. The bracket orients the flash lamp so that the light from the lamp is projected upward. A reflector is mounted at an angle on an adjustable arm and positioned directly above the flash lamp. The reflector is oriented so that light from the flash lamp strikes the reflector and is deflected in the direction of the subject being photographed. This provides a portable “ceiling” for a bounce flash. Sloop shows a similar device with two mounting brackets. A first bracket extends upward from a camera and holds a flash lamp. A second bracket extends from the first and holds a reflector at an angle above the flash lamp. This assembly is cumbersome, in that it requires a bracket to hold a camera, the flash lamp, and the reflector together as a unit.
Blizzard, Lowell et al., and Beverly show bounce light deflectors and diffusers that are similar to the previous devices, except they attach directly to the flash lamp assembly. Lowell's device primarily shapes the beam of light leaving the flash.
Kean shows a reflector that mounts onto a camera and through multiple reflections enlarges the area of the camera's own forward-facing flash. Light leaving the reflector is directed along the lens axis of the camera. This reflector only enlarges the apparent area of the flash lamp. The bounce effect is limited since light is not bounced from a distant surface.
Smith et al. show a reflector assembly similar to a periscope that is mounted on a camera. Light from the camera's own flash unit emerges parallel to, but is displaced from the camera's flash lamp. This device is helpful in reducing “red-eye”, the retinal reflection that commonly occurs when light from the camera's flash is reflected from a subject's eyes back into the camera's lens. This assembly does not effectively enlarge the source of light by bouncing the light off a distant surface, such as a ceiling.
Other prior-art devices, such as the model Mecablitz 58AF-1, manufactured by Metz-Werke GmbH & Co. KG, Zirndorf, Germany, incorporate a flash lamp into a tilting reflector. The assembly comprising the lamp, reflector, and associated electronics mount in the “hot shoe” on a camera, in well-known fashion. The lamp assembly can also swivel on the shoe, providing a light source that can be beamed in many directions, thereby producing a bounce flash. This flash assembly can be arranged to act independently or in concert with the flash unit contained in a camera. Light emanates from this apparatus in only a single direction, thereby providing limited bounce capabilities.
Takematsu shows a swivel lamp similar to the above with the addition of a second flash lamp. A first lamp provides a movable bounce flash, while the second lamp directs its light toward the subject. While this apparatus provides bounced light, it requires two flash lamps and does little to prevent red-eye.
Hagiuda et al. show a flash assembly that combines a bounce flash, similar to the Mecablitz above, with a dimming structure for a forward-facing camera flash lamp. An external bounce flash mounts on a camera. The external flash includes a fold-down dimming plate that partially blocks the direct light from the camera's flash. Again, as in Takematsu, both direct and indirect light illuminate the subject for an improved result. As with the Mecablitz, however, the bounce light travels from the flash lamp to the bounce surface at only a single, predetermined angle.
Crouse shows a reflective device for use with a source of flash illumination for providing either indirect or simultaneous direct and indirect illumination of a subject. The amount of reflected illumination is variable through the use of means such as movable shutters or polarizer sheets mounted on the reflective member. The amount of direct illumination is determined by the size of a pass-through in the reflector. Bounce light provided by this device emanates at a predetermined angle with respect to the camera, thus only a single source of bounce light is produced.
Weaver et al. show a flash apparatus having two flash lamps. A first lamp and reflector are directed toward the subject. A second lamp and reflector rotate about an axis perpendicular to the line between the camera lens and the subject. A third, infrared, illumination source emanates vertically from the flash apparatus and bounces off a ceiling or panel above the camera that is parallel to the line between the camera lens and the subject. The infrared light reflected from the ceiling is received by the flash apparatus which determines the distance between the flash and the ceiling. This distance is used to calculate the proper angle of rotation of the second lamp in order to maximize illumination of the subject by that lamp. While this apparatus maximizes the light from the bounce lamp, it does not provide bounce light from a plurality of surfaces.
Spencer shows a similar illuminator apparatus that uses range finders on a camera to determine the vertical distance, D, from the camera to the ceiling and the horizontal distance, H, from the camera to the subject. These values are used by a logic circuit that drives a servomechanism to angularly position the illuminator on the camera for optimum illumination of the subject. As with Weaver, this illuminator provides optimal bounce light intensity from a single bounce surface, but not from a plurality of surfaces
Geissler shows several bounce flash assemblies, each comprising a single tubular flash lamp situated within a partitioned reflector. The reflectors are arranged to rotate about the axis of the flash lamp. Part of the reflector directs a portion of the light from the flash lamp in a first direction, while the rest of the reflector directs the remaining light in a second direction, thereby providing adjustable illumination of the subject. This bounce flash has similarities to the Mecablitz unit described above. Light is reflected from a horizontal bounce surface above, and possibly below, the camera. However, bounce light cannot be obtained from vertical surfaces such as walls located to the sides of the flash lamp.
Stone shows several devices that clamp onto flash guns. In a first device, a bracket that is attached to a flash lamp unit forms a slot for mounting reflectors and diffusers. In a second device, a clamp that slips over a flash lamp assembly includes slots into which reflectors and diffusers can be inserted. In a third device, a diffusion device that slips over a flash lamp assembly includes a slot that can retain a reflector. Stone's reflectors and diffusers are inserted into their slots at fixed angles and thus can not be rotated or pivoted to direct light in any desired direction.
All of the above prior-art deflectors and diffusers thus have one or more of the following disadvantages. While they all work as described, none combine a plurality of independently positionable, dual-purpose panels that independently tilt, pivot, move longitudinally and laterally with respect to the center of a flash lamp assembly in a simple structure.